package java.nio;

import System.Text.Encoding;
import System.Text.UnicodeEncoding;
import System.BitConverter;

/**
 * A byte buffer.
 *
 * <p> This class defines six categories of operations upon
 * byte buffers:
 *
 * <ul>
 *
 *   <li><p> Absolute and relative {@link #get() </code><i>get</i><code>} and
 *   {@link #put(byte) </code><i>put</i><code>} methods that read and write
 *   single bytes; </p></li>
 *
 *   <li><p> Relative {@link #get(byte[]) </code><i>bulk get</i><code>}
 *   methods that transfer contiguous sequences of bytes from this buffer
 *   into an array; </p></li>
 *
 *   <li><p> Relative {@link #put(byte[]) </code><i>bulk put</i><code>}
 *   methods that transfer contiguous sequences of bytes from a
 *   byte array or some other byte
 *   buffer into this buffer; </p></li>
 *
 *   <li><p> Absolute and relative {@link #getChar() </code><i>get</i><code>}
 *   and {@link #putChar(char) </code><i>put</i><code>} methods that read and
 *   write values of other primitive types, translating them to and from
 *   sequences of bytes in a particular byte order; </p></li>
 *
 *   <li><p> Methods for creating <i><a href="#views">view buffers</a></i>,
 *   which allow a byte buffer to be viewed as a buffer containing values of
 *   some other primitive type; and </p></li>
 *
 *   <li><p> Methods for {@link #compact </code>compacting<code>}, {@link
 *   #duplicate </code>duplicating<code>}, and {@link #slice
 *   </code>slicing<code>} a byte buffer.  </p></li>
 *
 * </ul>
 *
 * <p> Byte buffers can be created either by {@link #allocate
 * </code><i>allocation</i><code>}, which allocates space for the buffer's
 *
 * content, or by {@link #wrap(byte[]) </code><i>wrapping</i><code>} an
 * existing byte array  into a buffer.
 *
 * <a name="direct">
 * <h4> Direct <i>vs.</i> non-direct buffers </h4>
 *
 * <p> A byte buffer is either <i>direct</i> or <i>non-direct</i>.  Given a
 * direct byte buffer, the Java virtual machine will make a best effort to
 * perform native I/O operations directly upon it.  That is, it will attempt to
 * avoid copying the buffer's content to (or from) an intermediate buffer
 * before (or after) each invocation of one of the underlying operating
 * system's native I/O operations.
 *
 * <p> A direct byte buffer may be created by invoking the {@link
 * #allocateDirect(int) allocateDirect} factory method of this class.  The
 * buffers returned by this method typically have somewhat higher allocation
 * and deallocation costs than non-direct buffers.  The contents of direct
 * buffers may reside outside of the normal garbage-collected heap, and so
 * their impact upon the memory footprint of an application might not be
 * obvious.  It is therefore recommended that direct buffers be allocated
 * primarily for large, long-lived buffers that are subject to the underlying
 * system's native I/O operations.  In general it is best to allocate direct
 * buffers only when they yield a measureable gain in program performance.
 *
 * <p> A direct byte buffer may also be created by {@link
 * java.nio.channels.FileChannel#map </code>mapping<code>} a region of a file
 * directly into memory.  An implementation of the Java platform may optionally
 * support the creation of direct byte buffers from native code via JNI.  If an
 * instance of one of these kinds of buffers refers to an inaccessible region
 * of memory then an attempt to access that region will not change the buffer's
 * content and will cause an unspecified exception to be thrown either at the
 * time of the access or at some later time.
 *
 * <p> Whether a byte buffer is direct or non-direct may be determined by
 * invoking its {@link #isDirect isDirect} method.  This method is provided so
 * that explicit buffer management can be done in performance-critical code.
 *
 *
 * <a name="bin">
 * <h4> Access to binary data </h4>
 *
 * <p> This class defines methods for reading and writing values of all other
 * primitive types, except <tt>boolean</tt>.  Primitive values are translated
 * to (or from) sequences of bytes according to the buffer's current byte
 * order, which may be retrieved and modified via the {@link #order order}
 * methods.  Specific byte orders are represented by instances of the {@link
 * ByteOrder} class.  The initial order of a byte buffer is always {@link
 * ByteOrder#BIG_ENDIAN BIG_ENDIAN}.
 *
 * <p> For access to heterogenous binary data, that is, sequences of values of
 * different types, this class defines a family of absolute and relative
 * <i>get</i> and <i>put</i> methods for each type.  For 32-bit floating-point
 * values, for example, this class defines:
 *
 * <blockquote><pre>
 * float  {@link #getFloat()}
 * float  {@link #getFloat(int) getFloat(int index)}
 *  void  {@link #putFloat(float) putFloat(float f)}
 *  void  {@link #putFloat(int,float) putFloat(int index, float f)}</pre></blockquote>
 *
 * <p> Corresponding methods are defined for the types <tt>char</tt>,
 * <tt>short</tt>, <tt>int</tt>, <tt>long</tt>, and <tt>double</tt>.  The index
 * parameters of the absolute <i>get</i> and <i>put</i> methods are in terms of
 * bytes rather than of the type being read or written.
 *
 * <a name="views">
 *
 * <p> For access to homogeneous binary data, that is, sequences of values of
 * the same type, this class defines methods that can create <i>views</i> of a
 * given byte buffer.  A <i>view buffer</i> is simply another buffer whose
 * content is backed by the byte buffer.  Changes to the byte buffer's content
 * will be visible in the view buffer, and vice versa; the two buffers'
 * position, limit, and mark values are independent.  The {@link
 * #asFloatBuffer() asFloatBuffer} method, for example, creates an instance of
 * the {@link FloatBuffer} class that is backed by the byte buffer upon which
 * the method is invoked.  Corresponding view-creation methods are defined for
 * the types <tt>char</tt>, <tt>short</tt>, <tt>int</tt>, <tt>long</tt>, and
 * <tt>double</tt>.
 *
 * <p> View buffers have three important advantages over the families of
 * type-specific <i>get</i> and <i>put</i> methods described above:
 *
 * <ul>
 *
 *   <li><p> A view buffer is indexed not in terms of bytes but rather in terms
 *   of the type-specific size of its values;  </p></li>
 *
 *   <li><p> A view buffer provides relative bulk <i>get</i> and <i>put</i>
 *   methods that can transfer contiguous sequences of values between a buffer
 *   and an array or some other buffer of the same type; and  </p></li>
 *
 *   <li><p> A view buffer is potentially much more efficient because it will
 *   be direct if, and only if, its backing byte buffer is direct.  </p></li>
 *
 * </ul>
 *
 * <p> The byte order of a view buffer is fixed to be that of its byte buffer
 * at the time that the view is created.  </p>
 *
 *
 * <h4> Invocation chaining </h4>
 *
 * <p> Methods in this class that do not otherwise have a value to return are
 * specified to return the buffer upon which they are invoked.  This allows
 * method invocations to be chained.
 *
 *
 * The sequence of statements
 *
 * <blockquote><pre>
 * bb.putInt(0xCAFEBABE);
 * bb.putShort(3);
 * bb.putShort(45);</pre></blockquote>
 *
 * can, for example, be replaced by the single statement
 *
 * <blockquote><pre>
 * bb.putInt(0xCAFEBABE).putShort(3).putShort(45);</pre></blockquote>
 * 
 *
 *
 * @author Mark Reinhold
 * @author JSR-51 Expert Group
 * @version 1.48, 03/01/23
 * @since 1.4
 * @author Federico Pieri - Erxa
 * @version $Date: 2005/03/08 14:30:00 $ $Revision: 1.04 $
 */
public abstract class ByteBuffer extends Buffer
{
	// These fields are declared here rather than in Heap-X-Buffer in order to
	// reduce the number of virtual method invocations needed to access these
	// values, which is especially costly when coding small buffers.
	//
	protected final byte[]	m_Array;
	protected final int		m_Offset;
	protected boolean		m_BigEndian = true;
	protected boolean		m_IsReadOnly= false;

	// Creates a new buffer with the given mark, position, limit, capacity,
	// backing array, and array offset
	//
	protected ByteBuffer(int mark, int pos, int lim, int cap, byte[] hb, int offset)
	{
		super(mark, pos, lim, cap);
		m_Array	= hb;
		m_Offset= offset;
	}

	// Creates a new buffer with the given mark, position, limit, and capacity
	//
	protected ByteBuffer(int mark, int pos, int lim, int cap)
	{
		this(mark, pos, lim, cap, null, 0);
	}

	/**
	 * Allocates a new byte buffer.
	 *
	 * <p> The new buffer's position will be zero, its limit will be its
	 * capacity, and its mark will be undefined.  It will have a {@link #array
	 * </code>backing array<code>}, and its {@link #arrayOffset </code>array
	 * offset<code>} will be zero.
	 *
	 * @param  capacity
	 *         The new buffer's capacity, in bytes
	 *
	 * @return  The new byte buffer
	 *
	 * @throws  IllegalArgumentException
	 *          If the <tt>capacity</tt> is a negative integer
	 */
	public static ByteBuffer allocate(int capacity)
	{
		if (capacity < 0)
			throw new IllegalArgumentException();
		//return new ByteBuffer(-1, 0, capacity, capacity, new byte[capacity], 0);
		return new HeapByteBuffer(capacity, capacity);
	}

	/**
	 * Retrieves this buffer's byte order.
	 *
	 * <p> The byte order is used when reading or writing multibyte values, and
	 * when creating buffers that are views of this byte buffer.  The order of
	 * a newly-created byte buffer is always {@link ByteOrder#BIG_ENDIAN
	 * BIG_ENDIAN}.  </p>
	 *
	 * @return  This buffer's byte order
	 */
	public final Encoding order()
	{
		if (m_BigEndian)
			return Encoding.GetEncoding( UnicodeEncoding.get_BigEndianUnicode().get_EncodingName() );
		return Encoding.GetEncoding( UnicodeEncoding.get_Unicode().get_EncodingName() );
	}

	protected byte[] convertUbyteToByte(ubyte[] source)
	{
		byte[] dest = new byte[source.length];
		System.Buffer.BlockCopy(source, 0, dest, 0, source.length);
		return dest;
	}

	protected ubyte[] convertByteToUbyte(byte[] source)
	{
		ubyte[] dest = new ubyte[source.length];
		System.Buffer.BlockCopy(source, 0, dest, 0, source.length);
		return dest;
	}

	protected int ix(int i)
	{
		return i+ m_Offset;
	}

	public abstract byte _get(int i);	
	
	public abstract void _put(int i, byte b);

	public byte get()
	{
		return m_Array[ix( nextGetIndex() )];
	}

	/**
	 * Absolute <i>get</i> method.  Reads the byte at the given
	 * index. </p>
	 *
	 * @param  index
	 *         The index from which the byte will be read
	 *
	 * @return  The byte at the given index
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit
	 */
	public byte get(int i)
	{
		return m_Array[ix( checkIndex(i) )];
	}

	/**
	 * Relative bulk <i>get</i> method.
	 *
	 * <p> This method transfers bytes from this buffer into the given
	 * destination array.  If there are fewer bytes remaining in the
	 * buffer than are required to satisfy the request, that is, if
	 * <tt>length</tt>&nbsp;<tt>&gt;</tt>&nbsp;<tt>remaining()</tt>, then no
	 * bytes are transferred and a {@link BufferUnderflowException} is
	 * thrown.
	 *
	 * <p> Otherwise, this method copies <tt>length</tt> bytes from this
	 * buffer into the given array, starting at the current position of this
	 * buffer and at the given offset in the array.  The position of this
	 * buffer is then incremented by <tt>length</tt>.
	 *
	 * <p> In other words, an invocation of this method of the form
	 * <tt>src.get(dst,&nbsp;off,&nbsp;len)</tt> has exactly the same effect as
	 * the loop
	 *
	 * <pre>
	 *     for (int i = off; i < off + len; i++)
	 *         dst[i] = src.get(); </pre>
	 *
	 * except that it first checks that there are sufficient bytes in
	 * this buffer and it is potentially much more efficient. </p>
	 *
	 * @param  dst
	 *         The array into which bytes are to be written
	 *
	 * @param  offset
	 *         The offset within the array of the first byte to be
	 *         written; must be non-negative and no larger than
	 *         <tt>dst.length</tt>
	 *
	 * @param  length
	 *         The maximum number of bytes to be written to the given
	 *         array; must be non-negative and no larger than
	 *         <tt>dst.length - offset</tt>
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than <tt>length</tt> bytes
	 *          remaining in this buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If the preconditions on the <tt>offset</tt> and <tt>length</tt>
	 *          parameters do not hold
	 */
	public ByteBuffer get(byte[] dest, int offset, int length)
	{
		checkBounds(offset, length, dest.length);
		if ( length > remaining() )
			throw new BufferUnderflowException();
		System.arraycopy(m_Array, ix( position() ), dest, offset, length);
		position( position() + length );
		return this;
	}

	/**
	 * Relative bulk <i>get</i> method.
	 *
	 * <p> This method transfers bytes from this buffer into the given
	 * destination array.  An invocation of this method of the form
	 * <tt>src.get(a)</tt> behaves in exactly the same way as the invocation
	 *
	 * <pre>
	 *     src.get(a, 0, a.length) </pre>
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than <tt>length</tt> bytes
	 *          remaining in this buffer
	 */
	public ByteBuffer get(byte[] dst) 
	{
		return get(dst, 0, dst.length);
	}


	/**
	 * Relative <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
	 * 
	 * <p> Writes the given byte into this buffer at the current
	 * position, and then increments the position. </p>
	 *
	 * @param  b
	 *         The byte to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If this buffer's current position is not smaller than its limit
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
    public ByteBuffer put (byte x)
	{
		m_Array[ix( nextPutIndex() )] = x;
		return this;
	}

	/**
	 * Absolute <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
	 * 
	 * <p> Writes the given byte into this buffer at the given
	 * index. </p>
	 *
	 * @param  index
	 *         The index at which the byte will be written
	 *
	 * @param  b
	 *         The byte value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public ByteBuffer put(int i, byte x)
	{
		m_Array[ix( checkIndex(i) )] = x;
		return this;
	}

	/**
	 * Relative bulk <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> This method transfers bytes into this buffer from the given
	 * source array.  If there are more bytes to be copied from the array
	 * than remain in this buffer, that is, if
	 * <tt>length</tt>&nbsp;<tt>&gt;</tt>&nbsp;<tt>remaining()</tt>, then no
	 * bytes are transferred and a {@link BufferOverflowException} is
	 * thrown.
	 *
	 * <p> Otherwise, this method copies <tt>length</tt> bytes from the
	 * given array into this buffer, starting at the given offset in the array
	 * and at the current position of this buffer.  The position of this buffer
	 * is then incremented by <tt>length</tt>.
	 *
	 * <p> In other words, an invocation of this method of the form
	 * <tt>dst.put(src,&nbsp;off,&nbsp;len)</tt> has exactly the same effect as
	 * the loop
	 *
	 * <pre>
	 *     for (int i = off; i < off + len; i++)
	 *         dst.put(a[i]); </pre>
	 *
	 * except that it first checks that there is sufficient space in this
	 * buffer and it is potentially much more efficient. </p>
	 *
	 * @param  src
	 *         The array from which bytes are to be read
	 *
	 * @param  offset
	 *         The offset within the array of the first byte to be read;
	 *         must be non-negative and no larger than <tt>array.length</tt>
	 *
	 * @param  length
	 *         The number of bytes to be read from the given array;
	 *         must be non-negative and no larger than
	 *         <tt>array.length - offset</tt>
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there is insufficient space in this buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If the preconditions on the <tt>offset</tt> and <tt>length</tt>
	 *          parameters do not hold
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	private ByteBuffer put (byte[] src, int offset, int length)
	{
		checkBounds(offset, length, src.length);
		if (length > remaining())
			throw new BufferOverflowException();
		int end = offset + length;
		for (int i = offset; i < end; i++)
			this.put(src[i]);
		return this;
	}

	/**
	 * Relative bulk <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> This method transfers the bytes remaining in the given source
	 * buffer into this buffer.  If there are more bytes remaining in the
	 * source buffer than in this buffer, that is, if
	 * <tt>src.remaining()</tt>&nbsp;<tt>&gt;</tt>&nbsp;<tt>remaining()</tt>,
	 * then no bytes are transferred and a {@link
	 * BufferOverflowException} is thrown.
	 *
	 * <p> Otherwise, this method copies
	 * <i>n</i>&nbsp;=&nbsp;<tt>src.remaining()</tt> bytes from the given
	 * buffer into this buffer, starting at each buffer's current position.
	 * The positions of both buffers are then incremented by <i>n</i>.
	 *
	 * <p> In other words, an invocation of this method of the form
	 * <tt>dst.put(src)</tt> has exactly the same effect as the loop
	 *
	 * <pre>
	 *     while (src.hasRemaining())
	 *         dst.put(src.get()); </pre>
	 *
	 * except that it first checks that there is sufficient space in this
	 * buffer and it is potentially much more efficient. </p>
	 *
	 * @param  src
	 *         The source buffer from which bytes are to be read;
	 *         must not be this buffer
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there is insufficient space in this buffer
	 *          for the remaining bytes in the source buffer
	 *
	 * @throws  IllegalArgumentException
	 *          If the source buffer is this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public ByteBuffer put (ByteBuffer src)
	{
		if (src == this)
			throw new IllegalArgumentException();
		int n = src.remaining();
		if ( n > remaining() )
			throw new BufferOverflowException();
		for (int i = 0; i < n; i++)
			put(src.get());
		return this;
	}

	/**
	 * Relative bulk <i>put</i> method&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> This method transfers the entire content of the given source
	 * byte array into this buffer.  An invocation of this method of the
	 * form <tt>dst.put(a)</tt> behaves in exactly the same way as the
	 * invocation
	 *
	 * <pre>
	 *     dst.put(a, 0, a.length) </pre>
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there is insufficient space in this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public final ByteBuffer put(byte[] src)
	{
		return put(src, 0, src.length);
	}

	/**
	 * Compacts this buffer&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> The bytes between the buffer's current position and its limit,
	 * if any, are copied to the beginning of the buffer.  That is, the
	 * byte at index <i>p</i>&nbsp;=&nbsp;<tt>position()</tt> is copied
	 * to index zero, the byte at index <i>p</i>&nbsp;+&nbsp;1 is copied
	 * to index one, and so forth until the byte at index
	 * <tt>limit()</tt>&nbsp;-&nbsp;1 is copied to index
	 * <i>n</i>&nbsp;=&nbsp;<tt>limit()</tt>&nbsp;-&nbsp;<tt>1</tt>&nbsp;-&nbsp;<i>p</i>.
	 * The buffer's position is then set to <i>n+1</i> and its limit is set to
	 * its capacity.  The mark, if defined, is discarded.
	 *
	 * <p> The buffer's position is set to the number of bytes copied,
	 * rather than to zero, so that an invocation of this method can be
	 * followed immediately by an invocation of another relative <i>put</i>
	 * method. </p>
	 *

	 *
	 * <p> Invoke this method after writing data from a buffer in case the
	 * write was incomplete.  The following loop, for example, copies bytes
	 * from one channel to another via the buffer <tt>buf</tt>:
	 *
	 * <blockquote><pre>
	 * buf.clear();          // Prepare buffer for use
	 * for (;;) {
	 *     if (in.read(buf) < 0 && !buf.hasRemaining())
	 *         break;        // No more bytes to transfer
	 *     buf.flip();
	 *     out.write(buf);
	 *     buf.compact();    // In case of partial write
	 * }</pre></blockquote>
	 * 

	 *
	 * @return  This buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public ByteBuffer compact()
	{
		System.arraycopy( m_Array, ix( position() ), m_Array,  ix(0), remaining() );
		position( remaining() );
		limit( capacity() );
		return this;
	}

	/**
	 * Relative <i>get</i> method for reading a char value.
	 *
	 * <p> Reads the next two bytes at this buffer's current position,
	 * composing them into a char value according to the current byte order,
	 * and then increments the position by two.  </p>
	 *
	 * @return  The char value at the buffer's current position
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than two bytes
	 *          remaining in this buffer
	 */
	public abstract char getChar();

	/**
	 * Relative <i>put</i> method for writing a char
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes two bytes containing the given char value, in the
	 * current byte order, into this buffer at the current position, and then
	 * increments the position by two.  </p>
	 *
	 * @param  value
	 *         The char value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there are fewer than two bytes
	 *          remaining in this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putChar(char value);

	/**
	 * Absolute <i>get</i> method for reading a char value.
	 *
	 * <p> Reads two bytes at the given index, composing them into a
	 * char value according to the current byte order.  </p>
	 *
	 * @param  index
	 *         The index from which the bytes will be read
	 *
	 * @return  The char value at the given index
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus one
	 */
	public abstract char getChar(int index);

	/**
	 * Absolute <i>put</i> method for writing a char
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes two bytes containing the given char value, in the
	 * current byte order, into this buffer at the given index.  </p>
	 *
	 * @param  index
	 *         The index at which the bytes will be written
	 *
	 * @param  value
	 *         The char value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus one
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putChar(int index, char value);

	/**
	 * Relative <i>get</i> method for reading a short value.
	 *
	 * <p> Reads the next two bytes at this buffer's current position,
	 * composing them into a short value according to the current byte order,
	 * and then increments the position by two.  </p>
	 *
	 * @return  The short value at the buffer's current position
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than two bytes
	 *          remaining in this buffer
	 */
	public abstract short getShort();

	/**
	 * Relative <i>put</i> method for writing a short
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes two bytes containing the given short value, in the
	 * current byte order, into this buffer at the current position, and then
	 * increments the position by two.  </p>
	 *
	 * @param  value
	 *         The short value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there are fewer than two bytes
	 *          remaining in this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putShort(short value);

	/**
	 * Absolute <i>get</i> method for reading a short value.
	 *
	 * <p> Reads two bytes at the given index, composing them into a
	 * short value according to the current byte order.  </p>
	 *
	 * @param  index
	 *         The index from which the bytes will be read
	 *
	 * @return  The short value at the given index
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus one
	 */
	public abstract short getShort(int index);

	/**
	 * Absolute <i>put</i> method for writing a short
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes two bytes containing the given short value, in the
	 * current byte order, into this buffer at the given index.  </p>
	 *
	 * @param  index
	 *         The index at which the bytes will be written
	 *
	 * @param  value
	 *         The short value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus one
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putShort(int index, short value);

	/**
	 * Relative <i>get</i> method for reading an int value.
	 *
	 * <p> Reads the next four bytes at this buffer's current position,
	 * composing them into an int value according to the current byte order,
	 * and then increments the position by four.  </p>
	 *
	 * @return  The int value at the buffer's current position
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than four bytes
	 *          remaining in this buffer
	 */
	public abstract int getInt();

	/**
	 * Relative <i>put</i> method for writing an int
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes four bytes containing the given int value, in the
	 * current byte order, into this buffer at the current position, and then
	 * increments the position by four.  </p>
	 *
	 * @param  value
	 *         The int value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there are fewer than four bytes
	 *          remaining in this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putInt(int value);

	/**
	 * Absolute <i>get</i> method for reading an int value.
	 *
	 * <p> Reads four bytes at the given index, composing them into a
	 * int value according to the current byte order.  </p>
	 *
	 * @param  index
	 *         The index from which the bytes will be read
	 *
	 * @return  The int value at the given index
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus three
	 */
	public abstract int getInt(int index);

	/**
	 * Absolute <i>put</i> method for writing an int
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes four bytes containing the given int value, in the
	 * current byte order, into this buffer at the given index.  </p>
	 *
	 * @param  index
	 *         The index at which the bytes will be written
	 *
	 * @param  value
	 *         The int value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus three
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putInt(int index, int value);

	/**
	 * Relative <i>get</i> method for reading a long value.
	 *
	 * <p> Reads the next eight bytes at this buffer's current position,
	 * composing them into a long value according to the current byte order,
	 * and then increments the position by eight.  </p>
	 *
	 * @return  The long value at the buffer's current position
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than eight bytes
	 *          remaining in this buffer
	 */
	public abstract long getLong();

	/**
	 * Relative <i>put</i> method for writing a long
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes eight bytes containing the given long value, in the
	 * current byte order, into this buffer at the current position, and then
	 * increments the position by eight.  </p>
	 *
	 * @param  value
	 *         The long value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there are fewer than eight bytes
	 *          remaining in this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putLong(long value);

	/**
	 * Absolute <i>get</i> method for reading a long value.
	 *
	 * <p> Reads eight bytes at the given index, composing them into a
	 * long value according to the current byte order.  </p>
	 *
	 * @param  index
	 *         The index from which the bytes will be read
	 *
	 * @return  The long value at the given index
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus seven
	 */
	public abstract long getLong(int index);

	/**
	 * Absolute <i>put</i> method for writing a long
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes eight bytes containing the given long value, in the
	 * current byte order, into this buffer at the given index.  </p>
	 *
	 * @param  index
	 *         The index at which the bytes will be written
	 *
	 * @param  value
	 *         The long value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus seven
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putLong(int index, long value);

	/**
	 * Relative <i>get</i> method for reading a float value.
	 *
	 * <p> Reads the next four bytes at this buffer's current position,
	 * composing them into a float value according to the current byte order,
	 * and then increments the position by four.  </p>
	 *
	 * @return  The float value at the buffer's current position
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than four bytes
	 *          remaining in this buffer
	 */
	public abstract float getFloat();

	/**
	 * Relative <i>put</i> method for writing a float
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes four bytes containing the given float value, in the
	 * current byte order, into this buffer at the current position, and then
	 * increments the position by four.  </p>
	 *
	 * @param  value
	 *         The float value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there are fewer than four bytes
	 *          remaining in this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putFloat(float value);

	/**
	 * Absolute <i>get</i> method for reading a float value.
	 *
	 * <p> Reads four bytes at the given index, composing them into a
	 * float value according to the current byte order.  </p>
	 *
	 * @param  index
	 *         The index from which the bytes will be read
	 *
	 * @return  The float value at the given index
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus three
	 */
	public abstract float getFloat(int index);

	/**
	 * Absolute <i>put</i> method for writing a float
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes four bytes containing the given float value, in the
	 * current byte order, into this buffer at the given index.  </p>
	 *
	 * @param  index
	 *         The index at which the bytes will be written
	 *
	 * @param  value
	 *         The float value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus three
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putFloat(int index, float value);

	/**
	 * Relative <i>get</i> method for reading a double value.
	 *
	 * <p> Reads the next eight bytes at this buffer's current position,
	 * composing them into a double value according to the current byte order,
	 * and then increments the position by eight.  </p>
	 *
	 * @return  The double value at the buffer's current position
	 *
	 * @throws  BufferUnderflowException
	 *          If there are fewer than eight bytes
	 *          remaining in this buffer
	 */
	public abstract double getDouble();

	/**
	 * Relative <i>put</i> method for writing a double
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes eight bytes containing the given double value, in the
	 * current byte order, into this buffer at the current position, and then
	 * increments the position by eight.  </p>
	 *
	 * @param  value
	 *         The double value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  BufferOverflowException
	 *          If there are fewer than eight bytes
	 *          remaining in this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putDouble(double value);

	/**
	 * Absolute <i>get</i> method for reading a double value.
	 *
	 * <p> Reads eight bytes at the given index, composing them into a
	 * double value according to the current byte order.  </p>
	 *
	 * @param  index
	 *         The index from which the bytes will be read
	 *
	 * @return  The double value at the given index
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus seven
	 */
	public abstract double getDouble(int index);

	/**
	 * Absolute <i>put</i> method for writing a double
	 * value&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Writes eight bytes containing the given double value, in the
	 * current byte order, into this buffer at the given index.  </p>
	 *
	 * @param  index
	 *         The index at which the bytes will be written
	 *
	 * @param  value
	 *         The double value to be written
	 *
	 * @return  This buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If <tt>index</tt> is negative
	 *          or not smaller than the buffer's limit,
	 *          minus seven
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is read-only
	 */
	public abstract ByteBuffer putDouble(int index, double value);

    public ubyte[] getUByte()
	{
		return convertByteToUbyte( m_Array );
	}

	public void copyUByte(ubyte[] data)
	{
		byte[] data2 = convertUbyteToByte(data);
		for (int i=0; i<data.length; i++)
		{
			m_Array[position()] = data2[i];
			position( position() + 1 );
		}
	}

	/**
	 * Wraps a byte array into a buffer.
	 *
	 * <p> The new buffer will be backed by the the given byte array;
	 * that is, modifications to the buffer will cause the array to be modified
	 * and vice versa.  The new buffer's capacity will be
	 * <tt>array.length</tt>, its position will be <tt>offset</tt>, its limit
	 * will be <tt>offset + length</tt>, and its mark will be undefined.  Its
	 * {@link #array </code>backing array<code>} will be the given array, and
	 * its {@link #arrayOffset </code>array offset<code>} will be zero.  </p>
	 *
	 * @param  array
	 *         The array that will back the new buffer
	 *
	 * @param  offset
	 *         The offset of the subarray to be used; must be non-negative and
	 *         no larger than <tt>array.length</tt>.  The new buffer's position
	 *         will be set to this value.
	 *
	 * @param  length
	 *         The length of the subarray to be used;
	 *         must be non-negative and no larger than
	 *         <tt>array.length - offset</tt>.
	 *         The new buffer's limit will be set to <tt>offset + length</tt>.
	 *
	 * @return  The new byte buffer
	 *
	 * @throws  IndexOutOfBoundsException
	 *          If the preconditions on the <tt>offset</tt> and <tt>length</tt>
	 *          parameters do not hold
	 */
	public static ByteBuffer wrap(byte[] array, int offset, int length)
	{
		try
		{
			return new HeapByteBuffer(array, offset, length);
		}
		catch(IllegalArgumentException iae)
		{
			throw new IndexOutOfBoundsException();
		}
	}
	
	/**
	 * Wraps a byte array into a buffer.
	 *
	 * <p> The new buffer will be backed by the the given byte array;
	 * that is, modifications to the buffer will cause the array to be modified
	 * and vice versa.  The new buffer's capacity and limit will be
	 * <tt>array.length</tt>, its position will be zero, and its mark will be
	 * undefined.  Its {@link #array </code>backing array<code>} will be the
	 * given array, and its {@link #arrayOffset </code>array offset<code>} will
	 * be zero.  </p> 
	 *
	 * @param  array
	 *         The array that will back this buffer
	 *
	 * @return  The new byte buffer
	 */
	public static ByteBuffer wrap(byte[] array)
	{
		return wrap(array, 0, array.length);
	}

	/**
	 * Tells whether or not this buffer is backed by an accessible byte
	 * array.
	 *
	 * <p> If this method returns <tt>true</tt> then the {@link #array() array}
	 * and {@link #arrayOffset() arrayOffset} methods may safely be invoked.
	 * </p>
	 *
	 * @return  <tt>true</tt> if, and only if, this buffer
	 *          is backed by an array and is not read-only
	 */
	public final boolean hasArray() 
	{
		return (m_Array != null) && !m_IsReadOnly;
	}

   /**
	 * Returns the byte array that backs this
	 * buffer&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Modifications to this buffer's content will cause the returned
	 * array's content to be modified, and vice versa.
	 *
	 * <p> Invoke the {@link #hasArray hasArray} method before invoking this
	 * method in order to ensure that this buffer has an accessible backing
	 * array.  </p>
	 *
	 * @return  The array that backs this buffer
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is backed by an array but is read-only
	 *
	 * @throws  UnsupportedOperationException
	 *          If this buffer is not backed by an accessible array
	 */
	public final byte[] array()
	{
		if (m_Array == null)
			throw new UnsupportedOperationException();
		return m_Array;
	}

	/**
	 * Returns the unsigned byte array that backs this
	 * buffer&nbsp;&nbsp;<i>(optional operation)</i>.
	 *
	 * <p> Modifications to this buffer's content will cause the returned
	 * array's content to be modified, and vice versa.
	 *
	 * <p> Invoke the {@link #hasArray hasArray} method before invoking this
	 * method in order to ensure that this buffer has an accessible backing
	 * array.  </p>
	 *
	 * @return  The array that backs this buffer (unsigned byte array)
	 *
	 * @throws  ReadOnlyBufferException
	 *          If this buffer is backed by an array but is read-only
	 *
	 * @throws  UnsupportedOperationException
	 *          If this buffer is not backed by an accessible array
	 */
	public final ubyte[] uarray()
	{
		return convertByteToUbyte( array() );
	}

	/**
	 * Returns a string summarizing the state of this buffer.  </p>
	 *
	 * @return  A summary string
	 */
	public String toString() 
	{
		StringBuffer sb = new StringBuffer();
		sb.append(getClass().getName());
		sb.append("[pos=");
		sb.append(position());
		sb.append(" lim=");
		sb.append(limit());
		sb.append(" cap=");
		sb.append(capacity());
		sb.append("]");
		return sb.toString();
	}

	/**
	 * Returns the current hash code of this buffer.
	 *
	 * <p> The hash code of a byte buffer depends only upon its remaining
	 * elements; that is, upon the elements from <tt>position()</tt> up to, and
	 * including, the element at <tt>limit()</tt>&nbsp;-&nbsp;<tt>1</tt>.
	 *
	 * <p> Because buffer hash codes are content-dependent, it is inadvisable
	 * to use buffers as keys in hash maps or similar data structures unless it
	 * is known that their contents will not change.  </p>
	 *
	 * @return  The current hash code of this buffer
	 */
	public int hashCode() 
	{
		int h = 1;
		int p = position();
		for (int i = limit() - 1; i >= p; i--)
			h = 31 * h + (int)get(i);
		return h;
	}

	/**
	 * Tells whether or not this buffer is equal to another object.
	 *
	 * <p> Two byte buffers are equal if, and only if,
	 *
	 * <p><ol>
	 *
	 *   <li><p> They have the same element type,  </p></li>
	 *
	 *   <li><p> They have the same number of remaining elements, and
	 *   </p></li>
	 *
	 *   <li><p> The two sequences of remaining elements, considered
	 *   independently of their starting positions, are pointwise equal.
	 *   </p></li>
	 *
	 * </ol>
	 *
	 * <p> A byte buffer is not equal to any other type of object.  </p>
	 *
	 * @param  ob  The object to which this buffer is to be compared
	 *
	 * @return  <tt>true</tt> if, and only if, this buffer is equal to the
	 *           given object
	 */
	public boolean equals(Object ob) 
	{
		if (!(ob instanceof ByteBuffer))
			return false;
		ByteBuffer that = (ByteBuffer)ob;
		if (this.remaining() != that.remaining())
			return false;
		int p = this.position();
		for (int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j--) 
		{
			byte v1 = this.get(i);
			byte v2 = that.get(j);
			if (v1 != v2) 
			{
				if ((v1 != v1) && (v2 != v2))	// For float and double
					continue;
				return false;
			}
		}
		return true;
	}

	/**
	 * Compares this buffer to another object.
	 *
	 * <p> Two byte buffers are compared by comparing their sequences of
	 * remaining elements lexicographically, without regard to the starting
	 * position of each sequence within its corresponding buffer.
	 *
	 * <p> A byte buffer is not comparable to any other type of object.  </p>
	 *
	 * @return  A negative integer, zero, or a positive integer as this buffer
	 *		is less than, equal to, or greater than the given buffer
	 *
	 * @throws  ClassCastException
	 *          If the argument is not a byte buffer
	 */
	public int compareTo(Object ob) 
	{
		ByteBuffer that = (ByteBuffer)ob;
		int n = this.position() + Math.min(this.remaining(), that.remaining());
		for (int i = this.position(), j = that.position(); i < n; i++, j++) 
		{
			byte v1 = this.get(i);
			byte v2 = that.get(j);
			if (v1 == v2)
				continue;
			if ((v1 != v1) && (v2 != v2)) 	// For float and double
				continue;
			if (v1 < v2)
				return -1;
			return +1;
		}
		return this.remaining() - that.remaining();
	}

	/**
	 * Creates a new byte buffer whose content is a shared subsequence of
	 * this buffer's content.
	 *
	 * <p> The content of the new buffer will start at this buffer's current
	 * position.  Changes to this buffer's content will be visible in the new
	 * buffer, and vice versa; the two buffers' position, limit, and mark
	 * values will be independent.
	 *
	 * <p> The new buffer's position will be zero, its capacity and its limit
	 * will be the number of bytes remaining in this buffer, and its mark
	 * will be undefined.  The new buffer will be direct if, and only if, this
	 * buffer is direct, and it will be read-only if, and only if, this buffer
	 * is read-only.  </p>
	 *
	 * @return  The new byte buffer
	 */
	public abstract ByteBuffer slice();
	
	/**
	 * Creates a new byte buffer that shares this buffer's content.
	 *
	 * <p> The content of the new buffer will be that of this buffer.  Changes
	 * to this buffer's content will be visible in the new buffer, and vice
	 * versa; the two buffers' position, limit, and mark values will be
	 * independent.
	 *
	 * <p> The new buffer's capacity, limit, position, and mark values will be
	 * identical to those of this buffer.  The new buffer will be direct if,
	 * and only if, this buffer is direct, and it will be read-only if, and
	 * only if, this buffer is read-only.  </p>
	 *
	 * @return  The new byte buffer
	 */
	public abstract ByteBuffer duplicate();
	
	public boolean isReadOnly() 
	{
		return m_IsReadOnly;
	}

}
